1. Field of the Invention
This invention relates to a reproducing apparatus for a disc in which optical discs having different information data recorded thereon, such as a data disc on which letter or character data or picture data, such as Japanese dictionary data, English-Japanese dictionary data or encyclopedia data, are recorded, or an audio disc on which audio signals are recorded may be reproduced selectively. More particularly, it relates to a reproducing apparatus for a disc in which it is determined if the optical disc loaded in the reproducing apparatus is a data disc or an audio disc and in which the reproducing operation may be switched automatically between the data disc reproducing operation and the audio disc reproducing operation depending on the type of the loaded optical disc.
2. Description of the Prior Art
Among the discs on which information data are pre-recorded, there are a data disc on which letter or character data or picture data, such as Japanese dictionary data, English-Japanese dictionary data or encyclopedia data are recorded, and an audio disc, on which audio signals are recorded.
There is proposed a reproducing apparatus for a disc which enables reproduction of an optical disc which may be a data disc or an audio disc. For reproducing a data disc by such a disc reproducing system, the letter or character data or the picture data recorded on the data disc are read out by an optical pickup and the read-out data are displayed as visual data on the display by way of performing a data reproducing operation. For reproducing an audio disc on which audio signals are recorded, the audio signals recorded on the audio disc are read out by an optical pickup and the read-out signal data are outputted as audio signals for driving a speaker by means of an audio processing circuit by way of performing an audio signal reproducing operation.
In this manner, the reproducing operation for information signals recorded on the optical disc differs as a function of whether the disc is a data disc or an audio disc.
Therefore, when reproducing the optical disc with the use of the above mentioned reproducing apparatus for a disc, it is grasped in advance whether the optical disc loaded in the system is the data disc or the audio disc and the operating mode is set as a function of the disc type before proceeding to reproduction.
With such reproducing system for a disc, since the reproducing mode is selected as a function of the optical disc to be loaded, that is, as a function of whether the disc is the data disc or the audio disc, should a mistake be made in the selection of the reproducing mode, it becomes impossible to reproduce data from the disc loaded in the system.
For example, when the operating mode is set to the audio disc reproducing operation, and the data disc is loaded by mistake, the data signals read from the optical disc are reproduced as though they were musical sound signals, so that, in a majority of cases, only the voice as the noise is reproduced. As a matter of course, the letter or character data recorded on the data disc cannot be displayed as visible data.
Conversely, when the operating mode is set to the data disc reproducing operation, and the audio disc is loaded by mistake, the information data such as letter or character data or picture data to be recorded on the data disc or the processing data for these information data cannot be read, so that the operation of reproducing the data read out by the optical pickup cannot be performed. For example, the operation of reproducing the data read out from the optical disc cannot be performed in succession to the data read-out operation. Should the user become aware of the error in loading the disc or in the setting of the operating mode and exchange the disc or the mode setting, it becomes possible to reproduce the desired optical disc. However, should the user not become aware of the error in loading the disc or in the setting of the operating mode, it may occur that the error be mistaken for a trouble in the disc reproducing system. There is also an inconvenience in that a laborsome operation is necessitated for exchanging the disc or re-setting the operating mode.